Unity how to find load time?

I’d like to find the time between when I press the play button and when the game actually starts. Is there a builtin function or a system function I could use to measure this?

Good day.

Some option is configure in unity editor that script “SomeScript” is executed the first. In this script, at Awake(), store the value Time.time in a variable called like “InitialTime”

Then, in the first Update of this script, just do

TimeSpentLoading = Time.time - InitialTime;